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Tire sizes

225/55R17 tire size — and the 20-inch tire that matches it

A crossover and executive-saloon size whose closest twin runs a wheel three inches larger.

Metric notation · Passenger touring

Overall diameter
26.74 in
679 mm
Section width
8.86 in
225 mm
Sidewall height
4.87 in
124 mm
Aspect ratio
55%
sidewall as a share of width
Wheel diameter
17 in
the hole in the middle
Circumference
84.0 in
2134 mm
Revolutions per mile
754.1
geometric, not measured
Revolutions per km
468.6
geometric, not measured
Typical load index
82–99
1047–1709 lb per tire

A passenger tire's load index tracks its air volume, and volume tracks section width and sidewall height. Sizes in this class sit in the band that carries a typical two-tonne car with its rated payload across four tires.

The load-index range shown is the band this CLASS of size is typically produced in — not a list of what is in stock for this exact size today. Load index and speed symbol are printed on the sidewall of the specific tire you are holding, and the required minimum is on the placard of the specific vehicle you are fitting. Read both.

Nearest real sizes in imperial notation, same wheel

  • 32x11.50R1732.00 in tall+5.26 in
  • 33x10.50R1733.00 in tall+6.26 in
  • 33x12.50R1733.00 in tall+6.26 in

Compare any two sizes, including ones this site has no page for, in the comparison tool.

Compact crossovers in mid trim and executive saloons in base trim share this code — CR-V, Rogue, Tucson, and the 5-series and E-class in their smallest wheel option.

Three inches of wheel, one hundredth of an inch of tire

245/35R20 measures 26.75 in. This size measures 26.74 in. The difference is 0.03%.

One of them wraps a 17-inch wheel in 4.87 in of sidewall; the other wraps a 20-inch wheel in 3.38 in. The gap between those two sidewall figures is very nearly an inch and a half, and it is absorbed entirely by the three inches of extra wheel. Section width differs by 0.79 in.

This is the most extreme plus-size relationship in the catalogue that still holds the rolling diameter, and it is worth knowing that such a thing exists before assuming a 20-inch wheel implies a taller car.

The band this size sits in

Size Wheel Diameter Difference Sidewall
245/35R20 20 in 26.75 in +0.01 in 3.38 in
245/40R19 19 in 26.72 in 0.03 in 3.86 in
245/45R18 18 in 26.68 in 0.06 in 4.34 in
225/60R16 16 in 26.63 in 0.11 in 5.31 in

Five wheel diameters from 16 to 20 inches, and a total spread of 0.12 in between the tallest and the shortest. Sidewall runs from 5.31 in at one end to 3.38 in at the other, and that is the only axis on which they meaningfully differ.

Ten-millimetre steps either side

215/55R17 is 0.43 in shorter at 26.31 in; 235/55R17 is 0.43 in taller at 27.18 in. This size sits exactly between them because the aspect ratio and the wheel are held while the width moves in even 10 mm steps.

Going up in aspect ratio instead, 225/60R17 is 0.89 in taller at 27.63 in — more than twice the width step, from a smaller-looking change to the code.

Reinforced casings on a crossover size

A large share of the tires sold under this code are built to the reinforced or extra-load standard, which raises the reference inflation the casing is rated at and therefore the load it may carry. It does not change any dimension on this page — a reinforced 225/55R17 is 26.74 in tall like every other one. What the marking does and does not signify is covered in the XL and reinforced markings reference.

Related

Class: Passenger touring. Every figure above is computed from the size code, not stored — see how these numbers are calculated.